Malnutrition, Starvation and Refeeding ppt

Malnutrition

• Lack of nourishment due to inadequate amounts of calories, protein, vitamins, or minerals caused by improper diet, alterations in digestion or absorption, chronic disease, or a combination of these factors

Secondary Malnutrition

• Malnutrition due to a condition that prevents proper digestion or absorption, or significantly increases metabolic consumption
• Often accompanies and exacerbates other types of malnutrition
• Causative conditions:
• Loss of appetite (e.g., due to cancer, intestinal disease)
• Alteration of normal metabolism during infection/fever
• HIV/AIDS
• Cancer
• Prevention of nutrient absorption
• Diarrheal infection causing changes in GI epithelium
• Diversion of nutrients to parasitic agents themselves
• Hookworms, tapeworms, schistosome worm
• Malaria
• Importance of sanitary waste disposal and clean water in reducing secondary malnutrition

Micronutrient Malnutrition

• The most critical micronutrients are iron, iodine, zinc, vitamin A, and vitamin D
• Common deficiencies:
• Iron
• Vitamin B12
• Vitamin D (in developing countries)
• Iodine
• Water-soluble vitamins (e.g., vitamin C)

Vitamin C (Water-Soluble Vitamin)

• Functions: required for the biosynthesis of collagen, L-carnitine, and certain neurotransmitters; involved in protein metabolism; plays an important role in immune function and improves the absorption of nonheme iron
• Deficiency: Scurvy (fatigue, widespread connective tissue weakness, capillary fragility, inflammation of the gums)
• At-risk populations: people with severe intestinal malabsorption or cachexia, and some cancer patients

Vitamin B12 (Water-Soluble Vitamin)

• Functions: red blood cell formation, nervous system maintenance; used as a cofactor for enzymes involved in the synthesis of DNA, fatty acids, and myelin
• Deficiencies:
• Anemia (macrocytic anemia)
• Nerve degeneration
• Paralysis
• Smooth tongue
• Fatigue
• Dementia
• Depression
• Important notes:
• Pernicious anemia is an autoimmune condition in which antibodies to intrinsic factor are produced
• Malabsorption: parietal cells in the stomach produce intrinsic factors; patients with a history of gastric bypass surgery are at risk for developing a B12 deficiency
• Dietary insufficiency: vitamin B12 is stored in excess in the liver; patients who have followed a strict vegan diet for approximately three years may develop a B12 deficiency from a lack of dietary intake

Folate (Water-Soluble Vitamin)

• Function: red blood cell formation, new cell division, protein metabolism
• Deficiencies:
• Macrocytic anemia
• Diarrhea
• Smooth tongue
• Depression
• Heartburn
• Important notes:
• Folate is absorbed in the jejunum
• Celiac disease, short bowel syndrome, gastric bypass, or mesenteric vascular insufficiency can inhibit folate absorption
• Drugs such as methotrexate, phenytoin, sulfasalazine, and trimethoprim can antagonize folate utilization, inhibit its absorption, or conversion to its active form, resulting in folate deficiency
• Algebraism is a significant cause of folate deficiency
• Pregnancy, hemolytic anemia, and dialysis can also result in folate deficiency
• Folic acid supplementation of 400mcg/day is recommended during all pregnancies; 4 milligrams is recommended if there is an increased risk of neural tube defects

Thiamine (Vitamin B1, Water-Soluble Vitamin)

• Functions: coenzyme in anaerobic glycolysis, the Krebs cycle, and HMP shunt
• Deficiency: Wernicke's encephalopathy (a degenerative brain disorder caused by the lack of vitamin B1)
• Important notes:
• Lack of thiamine causes inhibition of anaerobic glycolysis, affecting the brain the most because the brain's primary source of energy is glucose
• People with alcoholism are particularly prone to this deficiency due to decreased intake of thiamine, decreased absorption from the gastrointestinal tract in the presence of alcohol, and inability to use thiamine effectively secondary to lack of magnesium as a cofactor for the binding of thiamine to thiamine-dependent enzymes

Vitamin D (Fat-Soluble Vitamin)

• Functions: essential for bone development, immune system regulation, and calcium metabolism
• Deficiency: rickets (in children) and osteomalacia (in adults)
• Important notes:
• High-risk populations include nursing home residents, elderly patients, women with osteoporosis, African American/Hispanic individuals, hospitalized patients, patients with chronic kidney disease, chronic liver disease, and patients with malabsorption syndromes

Vitamin K (Fat-Soluble Vitamin)

• Functions: coagulation, bone development, cardiovascular health
• Deficiency: bleeding, poor bone development, osteoporosis, and increased cardiovascular disease
• Important notes:
• Absorbed in the jejunum and ileum, transported by chylomicrons in circulation, and dependent on bile, pancreatic enzymes, and dietary fat content
• Vitamin K is not transported across the placenta efficiently
• All neonates have reduced vitamin K at birth
• Vitamin K supplementation is recommended for all neonates within 1 hour of birth